Updated RELENG documentation w.r.t. translations.

Author: dokterbob

RELENG.rst

@@ -9,6 +9,9 @@ Steps
 
 #. Pick release date.
 #. Create milestone on GitHub, organise open tickets.
+#. Push source translations to Transifex::
+    $ django-admin makemessages -l en
+    $ tx push -s
 #. Send out announcement to translators on Transifex.
 #. Bump version in :code:`setup.py`.
 #. Update supported Django/Python releases to match Django's.